Carburetor air box



June 15, 1948. F. G. ROHM CARBURE'IOR AIR-BOX 2 Sheets-Sheet 1 Fil ed Oct. 5, 1944 jzaezifai- Fearzc 6713 072270 June 15, 1948. 5 R M I cARBIjREToR AIR-BOX 2 Sheets-Sheet 2 Filed 00:, 5, 12544 Patented June 15, 1948 CARBURETOR'? AIR BOX.

Fredric G. Ronni, William'sport, Pa., assignor to Avco Manufacturing. Corporation, a corporation of Delaware Application October 5,1944, Serial No..'557,291

' 'l Claim.

The invention relates to carburetor air-boxes.

In the use of air-boxes for delivering-hot and cold air to carburetors used on an'intern-al combustion engine it has been found that retardance to the air by the box and a good mixture of hot and cold air influence the horse-power output of the engine.

One-object of the invention is to P vi an improved carburetor air-box, which selectively delivers hot or cold air or a mixture thereof to the carburetor, for achieving the maximum horse- 'power by the engine.

mixture thereof to a carburetor which'is simple y in construction and efficient in operation.

Other objectsof the invention will appear from the detailed description.

The invention consists in the several novel features hereinafter set forth and moreparticularly -defined by claim at the conclusion hereof.

In the drawings:

Fig. 1 is a perspective ofan air-box embodying the invention. 1?

"Fig.2 is a sectional perspective. Fig. 3 is a longitudinal section.

Fig. 4 is a section taken on line 4-4 of Fig. 3.

Fig; 5 is a perspective of the gate valve for controlling the delivery of hot air or cold air to the carburetor.

The invention is exemplified in an air-box which comprises a cylindrical tube 8 which is provided at its outer or upper end with a flange 9 by which the air-box may be connected to the air intake of a carburetor a indicated by dotted lines in Fig. 3. The lower or inner end of tube 8 is open and is surrounded by an annular chamber l3 which is formed in a casing which comprises a cylindrical wall Ill concentric with :and'spaced annularly from the tube 8, a bottom wall I l spaced ,irom'the inner end of the tube 8 for the flow of air. from the casing into the lower end of the tube 8 for the flow of air from chamber l3 into the inner or lower end of the tube 8, and a top wall I! which is joined to the tube 8 in spaced I relation from its upper end. The casing is also provided with an inlet leg or trunk l5 which is :substantially rectangular in cross-section 1 and formedor sides I I joined to the cylindrical wall 10, the bottom'wall I6'and a top formed by an extension of the top-wall 12 of the chamber I3.

The outer end of the inlet-leg I5 is provided with an inlet I8 for the entry of'cold air into the casing. This inlet has straight top and bottom members l9 and 20 joined by cylindrical-side portions 2|. The cold air may flowlongitudinally through the leg l5 to the chamber l3. A chamber 24 for hot air extends'transversely across the inlet leg adjacent cold air inlet l8 and is formed by a partially cylindrical transverse wall 25 and an inclined wall 26 betweenwwallfi and the top wall of the inlet leg. A tubular inlet 23 for hot air is connected to one end of chamber 24. An opening 24 is formed in the top of the inlet leg for the flow of hot air into said leg; The opposite end of chamber is provided With an end wall 21. "The inclined wall 26 between cylindrical portion 25 and the top wall of the inlet leg form a duct which slopes downwardly and laterally toward the chamber I3, and between the chamber '24 and the top of the inlet leg.- The inlet 23 is connected to a suitable'source ofv hot air, such for example as a heating jacket around the exhaust pipe of the. engine. Hot air entering the inlet 23 passes into the chamber 24 which extends transversely across the casing, and may flow downwardly and angularly into the inlet leg 'of the casing.

A valve or gate 30' is fixed toa shaft or rod 3| which extends across the top of the casing and is journ'aled therein. An arm 3| is fixed to ma 3| for selectively setting the gate 30 in positions for controlling the supply of hot, cold or mixed hot and cold air to the carburetor. The gate 30 extends transversely across the inlet le between the opening 24 and the cold air inlet l8 and is adapted toswing from an inclined position as illustrated in full lines in Fig. 3, to completely cutoff the entry of cold air into the 'inlet leg |5,to approximately horizontal position indicated by dotted lines in Fig. 3 to completely out 01f the entry of hot air into the inlet leg I5, or to any intermediate position ior'controlling the flow of a mixture of hot and cold air in-any desired proportions to the portion of the inlet leg leading to chamber l3. The controlled air, whether hot, cold or mixed hot and cold air, to the inlet leg flows longitudinally through the inlet leg to the chamber B. A straight vane or baffle 34 is centrally disposed in the inlet leg l5 between the gate 30 and the annular chamber [3; This vane functions to-directionally control the air to-fiow'in asubstantially-straight path through 1eg -l5"towa'rd ehamber lh-pre'vents any between-the inner end of the'tube 8 and the botv I v intothe-inlet leg under gate .30 and hot air will tom I i of chamber" l3. A vane 35 extends diametrically across tube 8 and from the bottom to the top thereof and functions to direct the: air from chamber 13 longitudinally through .tube 8 in a substantially straight path into the carburetor. The internal diametenofthe,-tube:;8 ;con+x forms to the extreme-outer edge offthesusualp-y carburetor inlet flare. The lower end of tube 8 is formed with a bead 8. which forms, a round and 35 in all positions of gate 30' will function as before described to cause the desired directional flow of the air through the inlet leg and the tube 8. When it is desired to deliver mixed hot and cold or tempered air to the carburetor, the gate 30 will be set into an intermediate position depending upon the proportion of hot and cold air desired. Cold air from inlet; 18 will then flow be directed into the leg between inclined wall 26 and the gate 30 so that both the hot and cold air will be unidirectional in leg l5. Vane 30 will prevent initiation of a swirl in the leg and causethemixed air to flow through the inlet leg n a sltraightened path into the annular chamber 13- -from-whicl1" the mixed air will flow in a directly upward path, being thus directioned by the vane'35'to prevent swirling of the air passing I to ,the inlet of the carburetor.

end of tube 8 and is directed by the vane 35 longitudinally of the tube in a substantia l straight path-without;substantial retardance to the air. This prevent turbulence or swirloi the air in transit through the tube and rtosthe carburetor which results in retardance of .the air. I I

when gate 30, is set to cut oft the flow of hot air to-the inlet leg and to permit only cold-air to flow to the carburetor.

1 provided with asector shaped ring 36. which is i provided ,with a slot 3'? for communicating with atubular hot'air outlet--38v in the end wall 21 of the hot airichamber 24. Whengate 3l) is set to completely or .nearlycut off the flow of hot air from chamber-24 5111130 the inlet leg, slot 3'! will wholly or partially register with the outlet' 38 and bleed some of the hot air from the chamber 24 thereby preventing overheating oi the exhaust system. This bleeding of the hotai-r'from the chamber 24 reduces the pressure therein so that and prevents undesirable pressure .ofqhot air in the chamber 24 when the gate is set to, admit a small proportion of hot air'into the inlet leg. A 1 drain 39 is connected to the bottom ll of the chamber l3 for the, condensate whichmayaccumulate in said chamber and is usuallyprovided with a valve 411 for controlling the discharge of V the condensate.-

.. The operation will be as ifollows: When it is desired to deliver only-hot air to the;carburetor.

air from inlet l8 to the inlet leg, as shown by full lines in Fig. 3, andhotairwillfiow from inlet 23 into chamber 24 and from chamber 23 downwardly and angularly intoi and toward, the inner end of the inlet leg where the vane 34 will direct the. air in a substantiallystraight path :to

If the gate 3G .isset into the position indicated by I dottedlines in Fig. 3 to supply onlycoldzair to the .carburetoryhot' airwill be bled from chamber -25 through slot 31 and outlet duct 38 while cold air; from inlet 18 will flow straight through the ,inletgleg into chamber l3 and-theninto tube 8 .rom. which inflows-t th carhu etonr- -,Va es 34 In practice it-has been found advantageous to bleed some of the. hot air fromthe, chamber 24 For this purposegate 33 is it will not be forced into the inletleg of thecasing the gate 38 will be set to cut off the entryof cold In practice, it has been found that the pressure drop of air to the carburetor is minimized by the directional control of with the minimurn of re- Itardance to, the flpw of the air;- $1213.17 a good mixture oi hot. and coldair is .attainediwhengdesired;

that. h flo q 'ai t e car i rt si un te and .thatlthe power. loss resulting fro the. use of the air-box is minimized. Y In practice it has also been iound-thatthe con struction and relative. proportions of? he parts are ofimportance in achieving th objectsf of the i -u l h e mf und t hehe sh o the tube 8 should be at least egual he-,-he ight I of the inlet leg l5, preferably greater in; height, and thatthe vane 34 should be'otsufiicient length to prevent an initiation; of swirling of t heair to the inlet -leg: ,For example jn 31 ,100} with: an inlet leg a-.-%' in height and,4 ,'ini;.vvidth; a hot air chamber 24,-;3 A;" in diameter; an annuheight; and a tube 8.2 1 in diameterg-thevane 34 should'be at -,least 1' in; width. and-l the rvane 35 sh0uld;beatleast. 3 1.. inheighta With these proportions it has been; pun that hegpressure drop caused by the boxwf, h to the carburetorwill be reducediQ-at. eminimum. the flowto the .carburet'or will. be; iindisturbedaiiand the' resultant:-.power lossqw' be reduce.d..-to a minimum. v 5i The-invention; exemplifies .a carburetorria'ir-box which is efiicient in its operation. andmrovids for good mixture of;hot andgcoldvair substantially unretarded flow to,the.carburetor:and alowipower loss, and ;has been: found by test to ;materially improve the-fuel distribution to the individual cylinderf theengine. l 1 i The invention is not to be understood 7 stricted to .the detailsset'forth sincenthese may 0, Having thusdescribed the-.x'invention;

gbe, modified. within .the scopewokthejappended claim without departing from the spirit and scope oithe invention;

claim as new and desire,;to-.-;secure. byl Letters Patentis: Adair-box formingiaiseparate, unitlrdrb'm a carburetonand attachable t'o thezoutsid" of; the

carburetor casing around the .outerZ-eridaoft the =inlet passage of the, carburetorzponiprising: a substantially straight cylindrical: tuba-having an outer end; for connection to the 'inlet Iegubf; the

airintake on the outside of thecarburetor and its 7 inner end open; a casing including aisubstantially cylindrical wall spaced from and forming-faicylindrical iportionj chambier-xaround the tubelvansend wall! joinednto the tubeadjacentiiits':outemend and an opposite @endawall spacediiromvtheropen 5 inner end of the tube, a substantially straight inlet leg extending substantially at right angles having one of its ends communicatively connected to the cylindrical chamber portion and a cold air inlet at its opposite end; a single substantially straight vane in and extending across the inlet leg adjacent the side of the casing substantially parallel with the axis in the tube; the casing including a wall forming an approximately cylindrical hot air chamber extending transversely across the inlet leg adjacent the outer end of the tube and communicatively connected with the inlet leg and provided with a hot air inlet connected to one end and a bleed opening at the opposite end of the hot air chamber; and a gate extending across and pivoted to swing from a position approximately parallel to one wall of the leg and across the inlet leg for controlling the flow of hot air from the hot air chamber to the inlet leg and. cold air through the inlet leg to the cylindrical chamber around the casing, the gate being provided with a wing for controlling the fiow through the bleed opening. FREDRIC G. ROHM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 829,345 Menns Aug. 21, 1906 1,289,425 Fekete Dec. 31, 1918 1,745,813 Ricardo Feb. 4, 1930 1,933,380 Mock Oct. 31, 1933 15 2,395,997 Eckel Mar. 5, 1946 FOREIGN PATENTS Number Country Date 813,765 France -1 June 8, 193? 848,266 France Oct. 26, 1939 474,373 Great Britain Oct. 29, 1937 

